This invention relates to a colour photographic print material containing at least one pyrrolo[1,2-b]-1,2,4-triazole as the cyan coupler.
Colour photographic print materials are in particular materials for producing colour reflection prints or display images which most frequently have a positive image. They are thus not recording materials like colour photographic films.
Pyrrolo[1,2-b]-1,2,4-triazoles are cyan couplers known, for example from EP 628 867, which yield very clear cyan dyes having a relatively short-wave absorption band and very high absorbance and thus allow economies of silver halide to be made. The cyan dyes of these couplers additionally exhibit very good stability when stored in darkness.
A disadvantage is that these couplers result in distorted colour reproduction of blue and cyan tones.
The object of the invention is to remedy this disadvantage so that the advantages of these couplers may be exploited.
It has surprisingly now been found that this object may be achieved in a material of the above-stated type having at least one red-sensitive silver halide emulsion layer containing at least one cyan coupler, at least one green-sensitive silver halide emulsion layer containing at least one magenta coupler and at least one blue-sensitive silver halide emulsion layer containing at least one yellow coupler, which material contains in the red-sensitive layer, of which there is at least one, at least one pyrrolo[1,2-b]-1,2,4-triazole cyan coupler of the formula (I) ##STR2##
in which
R.sub.1 means hydrogen or a substituent, PA1 X means a hydrogen atom or a leaving group and PA1 Y means OR.sub.2 or ##STR3## PA1 R.sub.2 means ##STR4## PA1 R.sub.3 means alkyl, PA1 R.sub.4 means hydrogen or R.sub.3, PA1 R.sub.5, R.sub.6, R.sub.8 and R.sub.9 mean hydrogen or a substituent, PA1 R.sub.7 means a substituent and PA1 Z means the remaining non-metallic members of a 3- to 8-membered ring, wherein Z may be further substituted, if a two-equivalent yellow coupler is associated with the red-sensitive layer, of which there is at least one. PA1 R.sub.31 means alkyl, preferably having 1 to 4 C atoms, in particular methyl, PA1 R.sub.32 means alkyl, preferably having 1 to 4 C atoms, in particular methyl, PA1 R.sub.33 means a hydrogen atom or alkyl, preferably having 1 to 4 C atoms, in particular methyl or PA1 R.sub.32 and R.sub.33 together mean the remaining members of a cyclopropyl residue, PA1 R.sub.34 means chlorine or alkoxy, PA1 R.sub.35 means --NHCO--R.sub.37, --SO.sub.2 NH--R.sub.37, --NHSO.sub.2 --R.sub.37, --COOR.sub.37, Cl, Br or alkoxy PA1 R.sub.36 means a hydrogen or chlorine atom, PA1 R.sub.37 means a substituent, in particular a ballast group and PA1 Q means the remaining members of a substituted imidazole, imidazolidinedione, oxazolidinedione or triazolidinedione ring, PA1 wherein the alkyl groups may be further substituted. PA1 R.sub.21 means an alkyl, alkenyl or aryl group, PA1 R.sub.22 and R.sub.23 mutually independently mean a hydrogen atom or an alkyl or alkoxy group having up to 16 C atoms, PA1 R.sub.24 means a hydrogen atom or an alkyl group, in particular a methyl group, PA1 R.sub.25 means a C.sub.1 -C.sub.3 alkylene group and PA1 X.sub.1 means an oxygen atom or a free electron pair, PA1 wherein alkyl groups may be further substituted. PA1 in a common emulsion in at least one coupler solvent, PA1 in three separate emulsions each optionally having at least one coupler solvent and PA1 in two emulsions, wherein the preferred arrangement is that in which the cyan coupler and the p-aminophenol ether are present together in one emulsion and the yellow coupler in the other emulsion.
wherein
or alkyl,
The yellow coupler is preferably used in the red-sensitive layer, of which there is at least one. The quantity of yellow coupler in the red-sensitive layer is in particular 1 to 10 mol. % of the quantity of the cyan coupler of the formula (I).
The two-equivalent yellow coupler used in the red-sensitive layer preferably has a coupling rate which is no more than five times the coupling rate of the pyrrolotriazole cyan coupler. The coupling rate is determined using a method described in J. Phot. Sci. 36, 1988, page 14.
Two-equivalent couplers almost always couple substantially faster than cyan couplers. It would have been expected that a cyan layer of the structure according to the invention would exhibit a colour change from the lower to higher densities, with the low densities exhibiting a strong shift towards yellow or green.
Surprisingly, however, this does not occur.
Preferred two-equivalent yellow couplers are acetanilides, in particular pivaloylacetanilides and malonic anilides, the leaving groups of which are attached to the coupler molecule via O or N and which are substituted by chlorine, alkoxy or aryloxy in the ortho position of the anilide portion.
Very particularly preferred two-equivalent yellow couplers are of the formula (III): ##STR5##
in which
In a preferred embodiment, the red-sensitive layer, of which there is at least one, additionally contains at least one N,N-disubstituted p-aminophenol ether of the formula (II) ##STR6##
in which
Addition of the compounds of the formula (II) also improves the reproduction of skin tones.
There are various possible arrangements for the combined incorporation of the cyan coupler, yellow coupler and p-aminophenol ether according to the invention in a single layer: the compounds may be present
Suitable pyrrolo[1,2-b]-1,2,4-triazole cyan couplers of the formula (I) are:
Nr. R.sub.1 X Y I-1 ##STR7## H ##STR8## I-2 ##STR9## ##STR10## ##STR11## I-3 t-C.sub.4 H.sub.9 ##STR12## ##STR13## I-4 ##STR14## ##STR15## ##STR16## I-5 ##STR17## H ##STR18## I-6 ##STR19## H ##STR20## I-7 ##STR21## H ##STR22##
Suitable compounds of the formula (II) are compounds of the following formula:
 ##STR23## Nr. R.sub.21 R.sub.22 R.sub.23 R.sub.24 II-1 --OC.sub.12 H.sub.25 (n) H H H II-2 --OC.sub.14 H.sub.29 (n) H H H II-3 --OC.sub.16 H33(n) H H H II-4 ##STR24## H H II-5 ##STR25## H H H II-6 --OC.sub.12 H.sub.25 (n) CH.sub.3 H H II-7 --OC.sub.12 H.sub.25 (n) OCH.sub.3 H H II-8 --OCH.sub.3 --OC.sub.12 H.sub.25 (n) H H II-9 --OC.sub.14 H.sub.29 (n) H H CH.sub.3 II-10 ##STR26## H H H II-11 --OC.sub.3 H.sub.7 (i) --OC.sub.3 H.sub.7 (i) --C.sub.3 H.sub.7 (i) H
The compounds of the formula (II) are in particular used in a quantity of 0.01 to 10 mol./mol. of the cyan coupler of the formula (I), preferably 0.04 to 2 mol./mol. of the cyan coupler.
Up to 25 wt. % of the cyan couplers of the formula (I) may be replaced by other cyan couplers.
Further preferred embodiments of the invention are to be found in the subordinate claims.
Suitable yellow couplers of the formula (III) are ##STR27## ##STR28## ##STR29##
Examples of colour photographic print materials are colour photographic paper, colour reversal photographic paper and semi-transparent display material. A review is given in Research Disclosure 37038 (1985), Research Disclosure 38957 (1996) and Research Disclosure 40145 (1997).
The photographic print materials consist of a support onto which at least one photosensitive silver halide emulsion layer is applied. Thin films and sheets are in particular suitable as supports. A review of support materials and the auxiliary layers applied to the front and reverse sides of which is given in Research Disclosure 37254, part 1 (1995), page 285 and in Research Disclosure 38957, part XV (1996), page 627.
The colour photographic print materials conventionally contain at least one red-sensitive, one green-sensitive and one blue-sensitive silver halide emulsion layer, optionally together with interlayers and protective layers.
Depending upon the type of the photographic print material, these layers may be differently arranged. This is demonstrated for the most important products:
Colour photographic paper and colour photographic display material conventionally have on the support, in the stated sequence, one blue-sensitive, yellow-coupling silver halide emulsion layer, one green-sensitive, magenta-coupling silver halide emulsion layer and one red-sensitive, cyan-coupling silver halide emulsion layer; a yellow filter layer is not required.
The number and arrangement of the photosensitive layers may be varied in order to achieve specific results. For example, colour papers may also contain differently sensitised interlayers, by means of which gradation may be influenced.
The substantial constituents of the photographic emulsion layers are binder, silver halide grains and colour couplers.
Details of suitable binders may be found in Research Disclosure 37254, part 2 (1995), page 286 and in Research Disclosure 38957, part II.A (1996), page 598.
Details of suitable silver halide emulsions, the production, ripening, stabilisation and spectral sensitisation thereof, including suitable spectral sensitisers, may be found in Research Disclosure 37254, part 3 (1995), page 286 and in Research Disclosure 37038, part XV (1995), page 89 and in Research Disclosure 38957, part V.A (1996), page 603.
Pentamethinecyanines having naphthothiazole, naphthoxazole or benzothiazole as basic terminal groups, which may be substituted by halogen, methyl or methoxy groups and be 9,11-alkylene, in particular 9,11-neopentylene linked, may be used as red sensitisers for the red-sensitive layer. The N,N' substituents may be C.sub.4 -C.sub.8 alkyl groups. The methine chain may additionally also bear substituents. Pentamethines having only one methyl group on the cyclohexene ring may also be used. The red sensitiser may be supersensitised and stabilised by the addition of heterocyclic mercapto compounds.
The red-sensitive layer may additionally be spectrally sensitised between 390 and 590 nm, preferably at 500 nm, in order to ensure improved differentiation of red tones.
The spectral sensitisers may be added to the photographic emulsion in dissolved form or as a dispersion. Both solution and dispersion may contain additives, such as wetting agents or buffers.
The spectral sensitiser or a combination of spectral sensitisers may be added before, during or after preparation of the emulsion.
Photographic print materials contain either silver chloride-bromide emulsions containing up to 80 mol. % AgBr or silver chloride-bromide emulsion containing greater than 95 mol. % AgCl.
Details relating to colour couplers may be found in Research Disclosure 37254, part 4 (1995), page 288, in Research Disclosure 37038, part II (1995), page 80 and in Research Disclosure 38957, part X.B (1996), page 616. The maximum absorption of the dyes formed from the couplers and the developer oxidation product is preferably within the following ranges: yellow coupler 440 to 450 nm, magenta coupler 540 to 560 nm, cyan coupler 640 to 670 nm.
The yellow couplers conventionally used in print materials associated with a blue-sensitive layer are almost without exception two-equivalent couplers of the pivaloyl-acetanilide and cyclopropylcarbonylacetanilide series.
The magenta couplers conventional in print materials are almost without exception those from the series of anilinopyrazolones, pyrazolo[5,1-c]-(1,2,4)triazoles or pyrazolo[1,5-b]-(1,2,4)triazoles.
The non-photosensitive interlayers generally located between layers of different spectral sensitivity may contain agents which prevent an undesirable diffusion of developer oxidation products from one photosensitive layer into another photo-sensitive layer with a different spectral sensitisation.
Suitable compounds (white couplers, scavengers or DOP scavengers) may be found in Research Disclosure 37254, part 7 (1995), page 292, in Research Disclosure 37038, part III (1995), page 84 and in Research Disclosure 38957, part X.D (1996), pages 621 et seq.
The photographic material may also contain UV light absorbing compounds, optical brighteners, spacers, filter dyes, formalin scavengers, light stabilisers, anti-oxidants, D.sub.min dyes, plasticisers (latices), biocides and additives to improve the stability of dyes and couplers, to reduce colour fogging and to reduce yellowing and others. Suitable compounds may be found in Research Disclosure 37254, part 8 (1995), page 292, in Research Disclosure 37038, parts IV, V, VI, VII, X, XI and XIII (1995), pages 84 et seq. and in Research Disclosure 38957, parts VI, VIII, IX and X (1996), pages 607 and 610 et seq..
The layers of colour photographic materials are conventionally hardened, i.e. the binder used, preferably gelatine, is crosslinked by appropriate chemical methods.
Suitable hardener substances may be found in Research Disclosure 37254, part 9 (1995), page 294, in Research Disclosure 37038, part XII (1995), page 86 and in Research Disclosure 38957, part II.B (1996), page 599.
Once exposed with an image, colour photographic materials are processed using different processes depending upon their nature. Details relating to processing methods and the necessary chemicals are disclosed in Research Disclosure 37254, part 10 (1995), page 294, in Research Disclosure 37038, parts XVI to XXIII (1995), pages 95 et seq. and in Research Disclosure 38957, parts XVIII, XIX and XX (1996), pages 630 et seq. together with example materials.